Carrier EverFRESH Operation, Service And Parts Manual page 27

Component Water Drain Valve (WDV)
Troubleshooting A closed or plugged WDV or filter housing could prevent any air from entering
Component EverFRESH Nitrogen Valve (EN)
Troubleshooting An open or leaky EN valve would allow N2 to go into the sensor sensing
AL962 Oxygen (O2) Out of Range
Cause: This is a notification alarm and does not pose a risk to fresh produce, however the benefit of
atmosphere control will be lost. O2 level reaches pulldown limit and then O2 exceeds 5% over
setpoint for 30 minutes.
Component Upper Fresh Air Panel
Troubleshooting Verify Upper Fresh Air Panel has not been opened.
Component EverFRESH Air Valve (EA)
Troubleshooting An EA that is stuck open can allow continuous flow of fresh air into the
Component Container Air Tightness
Troubleshooting Seal container where possible (access panels, rear doors, mounting
AL976 Air Compressor Internal Protector Open
Cause: EverFRESH Air Compressor (EAC) internal protector opens.
Component EverFRESH Air Compressor (EAC)
Troubleshooting Follow steps defined in AL929 EAC testing.
Component ML5 Controller
Troubleshooting Access function code Cd74 to perform an ML5 self-diagnostic test.
Table 4–1 Alarm Indications and Descriptions
the container. P20-3 tests valve operation.
Potential failure results:
• MPT pressure fails to change when the valve is energized. Check for
signs of blockage by removing the WDV housing and particulate filter
housings. Clean any debris. While removed, inspect the WDV and
associated piping for blockage.
• EA current not correct. Access function code Cd74 and perform an
ML5 self-check to verify the controller is functioning properly. If it fails,
replace the controller. If it passes self-check, replace the WDV.
chamber, causing an inaccurate reading. P20-5 tests this valve.
Potential failure results:
• If tests fail, remove the EN and verify the valve is not clogged or dam-
aged.
• EA current is not correct. Access function code Cd74 and perform a
ML5 self-check to verify the controller is functioning properly. If it fails,
replace the controller. If it passes self-check, replace the EN.
container when compressor on. Refer to troubleshooting in the AL929 alarm
section.
hardware, etc).
4–3 T-374